Authors: Amlan Chakraborty Sutirtha Chakraborty Venkatakrishna R Jala Jonathan M Thomas M Keith Sharp R Eric Berson Bodduluri Haribabu
Publish Date: 2016/05/02
Volume: 44, Issue: 10, Pages: 3032-3045
Abstract
This study demonstrated the effects of the directionality of oscillatory wall shear stress WSS on proliferation and proatherogenic gene expression ICAM ESelectin and IL6 in the presence of inflammatory mediators leukotriene B4 LTB4 and bacterial lipopolysaccharide LPS from endothelial cells grown in an orbiting culture dish Computational fluid dynamics CFD was applied to quantify the flow in the dish while an analytical solution representing an extension of Stokes second problem was used for validation Results indicated that WSS magnitude was relatively constant near the center of the dish and oscillated significantly 0–09 Pa near the side walls Experiments showed that LTB4 dominated the shear effects on cell proliferation and area Addition of LPS didn’t change proliferation but significantly affected cell area The expression of ICAM1 ESelectin and IL6 were altered by directional oscillatory shear index DOSI a measure of the biaxiality of oscillatory shear but not shear magnitude The significance of DOSI was further reinforced by the strength of its interactions with other atherogenic factors Hence directionality of shear appears to be an important factor in regulating gene expression and provides a potential explanation of the propensity for increased vascular lesions in regions in the arteries with oscillating biaxial flow
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